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commit aa7f67304d1a03180f463258aa6f15a8b434e77d upstream.
When the system has multiple domains do_sched_rt_period_timer()
can run on any CPU and may iterate over all rt_rq in
cpu_online_mask. This means when balance_runtime() is run for a
given rt_rq that rt_rq may be in a different rd than the current
processor. Thus if we use smp_processor_id() to get rd in
do_balance_runtime() we may borrow runtime from a rt_rq that is
not part of our rd.
This changes do_balance_runtime to get the rd from the passed in
rt_rq ensuring that we borrow runtime only from the correct rd
for the given rt_rq.
This fixes a BUG at kernel/sched/rt.c:687! in __disable_runtime
when we try reclaim runtime lent to other rt_rq but runtime has
been lent to a rt_rq in another rd.
Signed-off-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Mike Galbraith <bitbucket@online.de>
Cc: peterz@infradead.org
Link: http://lkml.kernel.org/r/1358186131-29494-1-git-send-email-sbohrer@rgmadvisors.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f44310b98ddb7f0d06550d73ed67df5865e3eda5 upstream.
I get the following warning every day with v3.7, once or
twice a day:
[ 2235.186027] WARNING: at /mnt/sda7/kernel/linux/arch/x86/kernel/apic/ipi.c:109 default_send_IPI_mask_logical+0x2f/0xb8()
As explained by Linus as well:
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| Once we've done the "list_add_rcu()" to add it to the
| queue, we can have (another) IPI to the target CPU that can
| now see it and clear the mask.
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| So by the time we get to actually send the IPI, the mask might
| have been cleared by another IPI.
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This patch also fixes a system hang problem, if the data->cpumask
gets cleared after passing this point:
if (WARN_ONCE(!mask, "empty IPI mask"))
return;
then the problem in commit 83d349f35e1a ("x86: don't send an IPI to
the empty set of CPU's") will happen again.
Signed-off-by: Wang YanQing <udknight@gmail.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: peterz@infradead.org
Cc: mina86@mina86.org
Cc: srivatsa.bhat@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/20130126075357.GA3205@udknight
[ Tidied up the changelog and the comment in the code. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ee61abb3223e28a1a14a8429c0319755d20d3e40 upstream.
Commit 1fb9341ac348 ("module: put modules in list much earlier") moved
some of the module initialization code around, and in the process
changed the exit paths too. But for the duplicate export symbol error
case the change made the ddebug_cleanup path jump to after the module
mutex unlock, even though it happens with the mutex held.
Rusty has some patches to split this function up into some helper
functions, hopefully the mess of complex goto targets will go away
eventually.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1fb9341ac34825aa40354e74d9a2c69df7d2c304 upstream.
Prarit's excellent bug report:
> In recent Fedora releases (F17 & F18) some users have reported seeing
> messages similar to
>
> [ 15.478160] kvm: Could not allocate 304 bytes percpu data
> [ 15.478174] PERCPU: allocation failed, size=304 align=32, alloc from
> reserved chunk failed
>
> during system boot. In some cases, users have also reported seeing this
> message along with a failed load of other modules.
>
> What is happening is systemd is loading an instance of the kvm module for
> each cpu found (see commit e9bda3b). When the module load occurs the kernel
> currently allocates the modules percpu data area prior to checking to see
> if the module is already loaded or is in the process of being loaded. If
> the module is already loaded, or finishes load, the module loading code
> releases the current instance's module's percpu data.
Now we have a new state MODULE_STATE_UNFORMED, we can insert the
module into the list (and thus guarantee its uniqueness) before we
allocate the per-cpu region.
Reported-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 0d21b0e3477395e7ff2acc269f15df6e6a8d356d upstream.
You should never look at such a module, so it's excised from all paths
which traverse the modules list.
We add the state at the end, to avoid gratuitous ABI break (ksplice).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 9067ac85d533651b98c2ff903182a20cbb361fcb upstream.
wake_up_process() should never wakeup a TASK_STOPPED/TRACED task.
Change it to use TASK_NORMAL and add the WARN_ON().
TASK_ALL has no other users, probably can be killed.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 9899d11f654474d2d54ea52ceaa2a1f4db3abd68 upstream.
putreg() assumes that the tracee is not running and pt_regs_access() can
safely play with its stack. However a killed tracee can return from
ptrace_stop() to the low-level asm code and do RESTORE_REST, this means
that debugger can actually read/modify the kernel stack until the tracee
does SAVE_REST again.
set_task_blockstep() can race with SIGKILL too and in some sense this
race is even worse, the very fact the tracee can be woken up breaks the
logic.
As Linus suggested we can clear TASK_WAKEKILL around the arch_ptrace()
call, this ensures that nobody can ever wakeup the tracee while the
debugger looks at it. Not only this fixes the mentioned problems, we
can do some cleanups/simplifications in arch_ptrace() paths.
Probably ptrace_unfreeze_traced() needs more callers, for example it
makes sense to make the tracee killable for oom-killer before
access_process_vm().
While at it, add the comment into may_ptrace_stop() to explain why
ptrace_stop() still can't rely on SIGKILL and signal_pending_state().
Reported-by: Salman Qazi <sqazi@google.com>
Reported-by: Suleiman Souhlal <suleiman@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 910ffdb18a6408e14febbb6e4b6840fd2c928c82 upstream.
Cleanup and preparation for the next change.
signal_wake_up(resume => true) is overused. None of ptrace/jctl callers
actually want to wakeup a TASK_WAKEKILL task, but they can't specify the
necessary mask.
Turn signal_wake_up() into signal_wake_up_state(state), reintroduce
signal_wake_up() as a trivial helper, and add ptrace_signal_wake_up()
which adds __TASK_TRACED.
This way ptrace_signal_wake_up() can work "inside" ptrace_request()
even if the tracee doesn't have the TASK_WAKEKILL bit set.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f56c3196f251012de9b3ebaff55732a9074fdaae upstream.
Commit 083b804c4d3e ("async: use workqueue for worker pool") made it
possible that async jobs are moved from pending to running out-of-order.
While pending async jobs will be queued and dispatched for execution in
the same order, nothing guarantees they'll enter "1) move self to the
running queue" of async_run_entry_fn() in the same order.
Before the conversion, async implemented its own worker pool. An async
worker, upon being woken up, fetches the first item from the pending
list, which kept the executing lists sorted. The conversion to
workqueue was done by adding work_struct to each async_entry and async
just schedules the work item. The queueing and dispatching of such work
items are still in order but now each worker thread is associated with a
specific async_entry and moves that specific async_entry to the
executing list. So, depending on which worker reaches that point
earlier, which is non-deterministic, we may end up moving an async_entry
with larger cookie before one with smaller one.
This broke __lowest_in_progress(). running->domain may not be properly
sorted and is not guaranteed to contain lower cookies than pending list
when not empty. Fix it by ensuring sort-inserting to the running list
and always looking at both pending and running when trying to determine
the lowest cookie.
Over time, the async synchronization implementation became quite messy.
We better restructure it such that each async_entry is linked to two
lists - one global and one per domain - and not move it when execution
starts. There's no reason to distinguish pending and running. They
behave the same for synchronization purposes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c1bf08ac26e92122faab9f6c32ea8aba94612dae upstream.
If some other kernel subsystem has a module notifier, and adds a kprobe
to a ftrace mcount point (now that kprobes work on ftrace points),
when the ftrace notifier runs it will fail and disable ftrace, as well
as kprobes that are attached to ftrace points.
Here's the error:
WARNING: at kernel/trace/ftrace.c:1618 ftrace_bug+0x239/0x280()
Hardware name: Bochs
Modules linked in: fat(+) stap_56d28a51b3fe546293ca0700b10bcb29__8059(F) nfsv4 auth_rpcgss nfs dns_resolver fscache xt_nat iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack lockd sunrpc ppdev parport_pc parport microcode virtio_net i2c_piix4 drm_kms_helper ttm drm i2c_core [last unloaded: bid_shared]
Pid: 8068, comm: modprobe Tainted: GF 3.7.0-0.rc8.git0.1.fc19.x86_64 #1
Call Trace:
[<ffffffff8105e70f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff81134106>] ? __probe_kernel_read+0x46/0x70
[<ffffffffa0180000>] ? 0xffffffffa017ffff
[<ffffffffa0180000>] ? 0xffffffffa017ffff
[<ffffffff8105e76a>] warn_slowpath_null+0x1a/0x20
[<ffffffff810fd189>] ftrace_bug+0x239/0x280
[<ffffffff810fd626>] ftrace_process_locs+0x376/0x520
[<ffffffff810fefb7>] ftrace_module_notify+0x47/0x50
[<ffffffff8163912d>] notifier_call_chain+0x4d/0x70
[<ffffffff810882f8>] __blocking_notifier_call_chain+0x58/0x80
[<ffffffff81088336>] blocking_notifier_call_chain+0x16/0x20
[<ffffffff810c2a23>] sys_init_module+0x73/0x220
[<ffffffff8163d719>] system_call_fastpath+0x16/0x1b
---[ end trace 9ef46351e53bbf80 ]---
ftrace failed to modify [<ffffffffa0180000>] init_once+0x0/0x20 [fat]
actual: cc:bb:d2:4b:e1
A kprobe was added to the init_once() function in the fat module on load.
But this happened before ftrace could have touched the code. As ftrace
didn't run yet, the kprobe system had no idea it was a ftrace point and
simply added a breakpoint to the code (0xcc in the cc:bb:d2:4b:e1).
Then when ftrace went to modify the location from a call to mcount/fentry
into a nop, it didn't see a call op, but instead it saw the breakpoint op
and not knowing what to do with it, ftrace shut itself down.
The solution is to simply give the ftrace module notifier the max priority.
This should have been done regardless, as the core code ftrace modification
also happens very early on in boot up. This makes the module modification
closer to core modification.
Link: http://lkml.kernel.org/r/20130107140333.593683061@goodmis.org
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reported-by: Frank Ch. Eigler <fche@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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commit 7b9205bd775afc4439ed86d617f9042ee9e76a71 upstream.
The seccomp path was using AUDIT_ANOM_ABEND from when seccomp mode 1
could only kill a process. While we still want to make sure an audit
record is forced on a kill, this should use a separate record type since
seccomp mode 2 introduces other behaviors.
In the case of "handled" behaviors (process wasn't killed), only emit a
record if the process is under inspection. This change also fixes
userspace examination of seccomp audit events, since it was considered
malformed due to missing fields of the AUDIT_ANOM_ABEND event type.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Julien Tinnes <jln@google.com>
Acked-by: Will Drewry <wad@chromium.org>
Acked-by: Steve Grubb <sgrubb@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 3935e89505a1c3ab3f3b0c7ef0eae54124f48905 upstream.
Commit 8d4516904b39 ("watchdog: Fix CPU hotplug regression") causes an
oops or hard lockup when doing
echo 0 > /proc/sys/kernel/nmi_watchdog
echo 1 > /proc/sys/kernel/nmi_watchdog
and the kernel is booted with nmi_watchdog=1 (default)
Running laptop-mode-tools and disconnecting/connecting AC power will
cause this to trigger, making it a common failure scenario on laptops.
Instead of bailing out of watchdog_disable() when !watchdog_enabled we
can initialize the hrtimer regardless of watchdog_enabled status. This
makes it safe to call watchdog_disable() in the nmi_watchdog=0 case,
without the negative effect on the enabled => disabled => enabled case.
All these tests pass with this patch:
- nmi_watchdog=1
echo 0 > /proc/sys/kernel/nmi_watchdog
echo 1 > /proc/sys/kernel/nmi_watchdog
- nmi_watchdog=0
echo 0 > /sys/devices/system/cpu/cpu1/online
- nmi_watchdog=0
echo mem > /sys/power/state
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=51661
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Cc: Norbert Warmuth <nwarmuth@t-online.de>
Cc: Joseph Salisbury <joseph.salisbury@canonical.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 5ba53ff648e785445a32ba39112ed07e4cf588d0 upstream.
Commit 77097ae503b1 ("most of set_current_blocked() callers want
SIGKILL/SIGSTOP removed from set") removed the initialization of newmask
by accident, causing ltp to complain like this:
ssetmask01 1 TFAIL : sgetmask() failed: TEST_ERRNO=???(0): Success
Restore the proper initialization.
Reported-and-tested-by: CAI Qian <caiqian@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 35dac27cedd14c3b6fcd4ba7bc3c31738cfd1831 upstream.
print_prefix() passes a NULL buf to print_time() to get the length of
the time prefix; when printk times are enabled, the current code just
returns the constant 15, which matches the format "[%5lu.%06lu] " used
to print the time value. However, this is obviously incorrect when the
whole seconds part of the time gets beyond 5 digits (100000 seconds is a
bit more than a day of uptime).
The simple fix is to use snprintf(NULL, 0, ...) to calculate the actual
length of the time prefix. This could be micro-optimized but it seems
better to have simpler, more readable code here.
The bug leads to the syslog system call miscomputing which messages fit
into the userspace buffer. If there are enough messages to fill
log_buf_len and some have a timestamp >= 100000, dmesg may fail with:
# dmesg
klogctl: Bad address
When this happens, strace shows that the failure is indeed EFAULT due to
the kernel mistakenly accessing past the end of dmesg's buffer, since
dmesg asks the kernel how big a buffer it needs, allocates a bit more,
and then gets an error when it asks the kernel to fill it:
syslog(0xa, 0, 0) = 1048576
mmap(NULL, 1052672, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fa4d25d2000
syslog(0x3, 0x7fa4d25d2010, 0x100008) = -1 EFAULT (Bad address)
As far as I can see, the bug has been there as long as print_time(),
which comes from commit 084681d14e42 ("printk: flush continuation lines
immediately to console") in 3.5-rc5.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.com>
Cc: Sylvain Munaut <s.munaut@whatever-company.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f33fddc2b9573d8359f1007d4bbe5cd587a0c093 upstream.
in cgroup_add_file,when creating files for cgroup,
some of creation may be skipped. So we need to avoid
deleting these uncreated files in cgroup_rm_file,
otherwise the warning msg will be triggered.
"cgroup_addrm_files: failed to remove memory_pressure_enabled, err=-2"
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 175431635ec09b1d1bba04979b006b99e8305a83 upstream.
cgroup_create_dir() does weird dancing with dentry refcnt. On
success, it gets and then puts it achieving nothing. On failure, it
puts but there isn't no matching get anywhere leading to the following
oops if cgroup_create_file() fails for whatever reason.
------------[ cut here ]------------
kernel BUG at /work/os/work/fs/dcache.c:552!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in:
CPU 2
Pid: 697, comm: mkdir Not tainted 3.7.0-rc4-work+ #3 Bochs Bochs
RIP: 0010:[<ffffffff811d9c0c>] [<ffffffff811d9c0c>] dput+0x1dc/0x1e0
RSP: 0018:ffff88001a3ebef8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88000e5b1ef8 RCX: 0000000000000403
RDX: 0000000000000303 RSI: 2000000000000000 RDI: ffff88000e5b1f58
RBP: ffff88001a3ebf18 R08: ffffffff82c76960 R09: 0000000000000001
R10: ffff880015022080 R11: ffd9bed70f48a041 R12: 00000000ffffffea
R13: 0000000000000001 R14: ffff88000e5b1f58 R15: 00007fff57656d60
FS: 00007ff05fcb3800(0000) GS:ffff88001fd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004046f0 CR3: 000000001315f000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process mkdir (pid: 697, threadinfo ffff88001a3ea000, task ffff880015022080)
Stack:
ffff88001a3ebf48 00000000ffffffea 0000000000000001 0000000000000000
ffff88001a3ebf38 ffffffff811cc889 0000000000000001 ffff88000e5b1ef8
ffff88001a3ebf68 ffffffff811d1fc9 ffff8800198d7f18 ffff880019106ef8
Call Trace:
[<ffffffff811cc889>] done_path_create+0x19/0x50
[<ffffffff811d1fc9>] sys_mkdirat+0x59/0x80
[<ffffffff811d2009>] sys_mkdir+0x19/0x20
[<ffffffff81be1e02>] system_call_fastpath+0x16/0x1b
Code: 00 48 8d 90 18 01 00 00 48 89 93 c0 00 00 00 4c 89 a0 18 01 00 00 48 8b 83 a0 00 00 00 83 80 28 01 00 00 01 e8 e6 6f a0 00 eb 92 <0f> 0b 66 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 49 89 fe 41
RIP [<ffffffff811d9c0c>] dput+0x1dc/0x1e0
RSP <ffff88001a3ebef8>
---[ end trace 1277bcfd9561ddb0 ]---
Fix it by dropping the unnecessary dget/dput() pair.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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css_set
commit 5edee61edeaaebafe584f8fb7074c1ef4658596b upstream.
cgroup core has a bug which violates a basic rule about event
notifications - when a new entity needs to be added, you add that to
the notification list first and then make the new entity conform to
the current state. If done in the reverse order, an event happening
inbetween will be lost.
cgroup_subsys->fork() is invoked way before the new task is added to
the css_set. Currently, cgroup_freezer is the only user of ->fork()
and uses it to make new tasks conform to the current state of the
freezer. If FROZEN state is requested while fork is in progress
between cgroup_fork_callbacks() and cgroup_post_fork(), the child
could escape freezing - the cgroup isn't frozen when ->fork() is
called and the freezer couldn't see the new task on the css_set.
This patch moves cgroup_subsys->fork() invocation to
cgroup_post_fork() after the new task is added to the css_set.
cgroup_fork_callbacks() is removed.
Because now a task may be migrated during cgroup_subsys->fork(),
freezer_fork() is updated so that it adheres to the usual RCU locking
and the rather pointless comment on why locking can be different there
is removed (if it doesn't make anything simpler, why even bother?).
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 04aa530ec04f61875b99c12721162e2964e3318c upstream.
Sankara reported that the genirq core code fails to adjust the
affinity of an interrupt thread in several cases:
1) On request/setup_irq() the call to setup_affinity() happens before
the new action is registered, so the new thread is not notified.
2) For secondary shared interrupts nothing notifies the new thread to
change its affinity.
3) Interrupts which have the IRQ_NO_BALANCE flag set are not moving
the thread either.
Fix this by setting the thread affinity flag right on thread creation
time. This ensures that under all circumstances the thread moves to
the right place. Requires a check in irq_thread_check_affinity for an
existing affinity mask (CONFIG_CPU_MASK_OFFSTACK=y)
Reported-and-tested-by: Sankara Muthukrishnan <sankara.m@gmail.com>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1209041738200.2754@ionos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 878d7439d0f45a95869e417576774673d1fa243f upstream.
Commit 29c00b4a1d9e27 (rcu: Add event-tracing for RCU callback
invocation) added a regression in rcu_do_batch()
Under stress, RCU is supposed to allow to process all items in queue,
instead of a batch of 10 items (blimit), but an integer overflow makes
the effective limit being 1. So, unless there is frequent idle periods
(during which RCU ignores batch limits), RCU can be forced into a
state where it cannot keep up with the callback-generation rate,
eventually resulting in OOM.
This commit therefore converts a few variables in rcu_do_batch() from
int to long to fix this problem, along with the module parameters
controlling the batch limits.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 9366c1ba13fbc41bdb57702e75ca4382f209c82f upstream.
The function rb_check_pages() was added to make sure the ring buffer's
pages were sane. This check is done when the ring buffer size is modified
as well as when the iterator is released (closing the "trace" file),
as that was considered a non fast path and a good place to do a sanity
check.
The problem is that the check does not have any locks around it.
If one process were to read the trace file, and another were to read
the raw binary file, the check could happen while the reader is reading
the file.
The issues with this is that the check requires to clear the HEAD page
before doing the full check and it restores it afterward. But readers
require the HEAD page to exist before it can read the buffer, otherwise
it gives a nasty warning and disables the buffer.
By adding the reader lock around the check, this keeps the race from
happening.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 54f7be5b831254199522523ccab4c3d954bbf576 upstream.
The function rb_set_head_page() searches the list of ring buffer
pages for a the page that has the HEAD page flag set. If it does
not find it, it will do a WARN_ON(), disable the ring buffer and
return NULL, as this should never happen.
But if this bug happens to happen, not all callers of this function
can handle a NULL pointer being returned from it. That needs to be
fixed.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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|
commit 70f77b3f7ec010ff9624c1f2e39a81babc9e2429 upstream.
There is a typo here where '&' is used instead of '|' and it turns the
statement into a noop. The original code is equivalent to:
iter->flags &= ~((1 << 2) & (1 << 4));
Link: http://lkml.kernel.org/r/20120609161027.GD6488@elgon.mountain
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull module signing fixes from Rusty Russell:
"David gave me these a month ago, during my git workflow churn :("
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
ASN.1: Fix an indefinite length skip error
MODSIGN: Don't use enum-type bitfields in module signature info block
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull watchdog fix from Thomas Gleixner:
"Trivial CPU hotplug regression fix for the watchdog code"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
watchdog: Fix CPU hotplug regression
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|
Don't use enum-type bitfields in the module signature info block as we can't be
certain how the compiler will handle them. As I understand it, it is arch
dependent, and it is possible for the compiler to rearrange them based on
endianness and to insert a byte of padding to pad the three enums out to four
bytes.
Instead use u8 fields for these, which the compiler should emit in the right
order without padding.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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|
Norbert reported:
"3.7-rc6 booted with nmi_watchdog=0 fails to suspend to RAM or
offline CPUs. It's reproducable with a KVM guest and physical
system."
The reason is that commit bcd951cf(watchdog: Use hotplug thread
infrastructure) missed to take this into account. So the cpu offline
code gets stuck in the teardown function because it accesses non
initialized data structures.
Add a check for watchdog_enabled into that path to cure the issue.
Reported-and-tested-by: Norbert Warmuth <nwarmuth@t-online.de>
Tested-by: Joseph Salisbury <joseph.salisbury@canonical.com>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1211231033230.2701@ionos
Link: http://bugs.launchpad.net/bugs/1079534
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull module fixes from Rusty Russell:
"Module signing build fixes for blackfin and metag"
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
modsign: add symbol prefix to certificate list
linux/kernel.h: define SYMBOL_PREFIX
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fixes from Tejun Heo:
"So, safe fixes my ass.
Commit 8852aac25e79 ("workqueue: mod_delayed_work_on() shouldn't queue
timer on 0 delay") had the side-effect of performing delayed_work
sanity checks even when @delay is 0, which should be fine for any sane
use cases.
Unfortunately, megaraid was being overly ingenious. It seemingly
wanted to use cancel_delayed_work_sync() before cancel_work_sync() was
introduced, but didn't want to waste the space for full delayed_work
as it was only going to use 0 @delay. So, it only allocated space for
struct work_struct and then cast it to struct delayed_work and passed
it into delayed_work functions - truly awesome engineering tradeoff to
save some bytes.
Xiaotian fixed it by making megraid allocate full delayed_work for
now. It should be converted to use work_struct and cancel_work_sync()
but I think we better do that after 3.7.
I added another commit to change BUG_ON()s in __queue_delayed_work()
to WARN_ON_ONCE()s so that the kernel doesn't crash even if there are
more such abuses."
* 'for-3.7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: convert BUG_ON()s in __queue_delayed_work() to WARN_ON_ONCE()s
megaraid: fix BUG_ON() from incorrect use of delayed work
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8852aac25e ("workqueue: mod_delayed_work_on() shouldn't queue timer on
0 delay") unexpectedly uncovered a very nasty abuse of delayed_work in
megaraid - it allocated work_struct, casted it to delayed_work and
then pass that into queue_delayed_work().
Previously, this was okay because 0 @delay short-circuited to
queue_work() before doing anything with delayed_work. 8852aac25e
moved 0 @delay test into __queue_delayed_work() after sanity check on
delayed_work making megaraid trigger BUG_ON().
Although megaraid is already fixed by c1d390d8e6 ("megaraid: fix
BUG_ON() from incorrect use of delayed work"), this patch converts
BUG_ON()s in __queue_delayed_work() to WARN_ON_ONCE()s so that such
abusers, if there are more, trigger warning but don't crash the
machine.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Xiaotian Feng <xtfeng@gmail.com>
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|
This reverts commit 800d4d30c8f20bd728e5741a3b77c4859a613f7c.
Between commits 8323f26ce342 ("sched: Fix race in task_group()") and
800d4d30c8f2 ("sched, autogroup: Stop going ahead if autogroup is
disabled"), autogroup is a wreck.
With both applied, all you have to do to crash a box is disable
autogroup during boot up, then reboot.. boom, NULL pointer dereference
due to commit 800d4d30c8f2 not allowing autogroup to move things, and
commit 8323f26ce342 making that the only way to switch runqueues:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff81063ac0>] effective_load.isra.43+0x50/0x90
Pid: 7047, comm: systemd-user-se Not tainted 3.6.8-smp #7 MEDIONPC MS-7502/MS-7502
RIP: effective_load.isra.43+0x50/0x90
Process systemd-user-se (pid: 7047, threadinfo ffff880221dde000, task ffff88022618b3a0)
Call Trace:
select_task_rq_fair+0x255/0x780
try_to_wake_up+0x156/0x2c0
wake_up_state+0xb/0x10
signal_wake_up+0x28/0x40
complete_signal+0x1d6/0x250
__send_signal+0x170/0x310
send_signal+0x40/0x80
do_send_sig_info+0x47/0x90
group_send_sig_info+0x4a/0x70
kill_pid_info+0x3a/0x60
sys_kill+0x97/0x1a0
? vfs_read+0x120/0x160
? sys_read+0x45/0x90
system_call_fastpath+0x16/0x1b
Code: 49 0f af 41 50 31 d2 49 f7 f0 48 83 f8 01 48 0f 46 c6 48 2b 07 48 8b bf 40 01 00 00 48 85 ff 74 3a 45 31 c0 48 8b 8f 50 01 00 00 <48> 8b 11 4c 8b 89 80 00 00 00 49 89 d2 48 01 d0 45 8b 59 58 4c
RIP [<ffffffff81063ac0>] effective_load.isra.43+0x50/0x90
RSP <ffff880221ddfbd8>
CR2: 0000000000000000
Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Yong Zhang <yong.zhang0@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@vger.kernel.org # 2.6.39+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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|
Add the arch symbol prefix (if applicable) to the asm definition of
modsign_certificate_list and modsign_certificate_list_end. This uses the
recently defined SYMBOL_PREFIX which is derived from
CONFIG_SYMBOL_PREFIX.
This fixes the build of module signing on the blackfin and metag
architectures.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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8376fe22c7 ("workqueue: implement mod_delayed_work[_on]()")
implemented mod_delayed_work[_on]() using the improved
try_to_grab_pending(). The function is later used, among others, to
replace [__]candel_delayed_work() + queue_delayed_work() combinations.
Unfortunately, a delayed_work item w/ zero @delay is handled slightly
differently by mod_delayed_work_on() compared to
queue_delayed_work_on(). The latter skips timer altogether and
directly queues it using queue_work_on() while the former schedules
timer which will expire on the closest tick. This means, when @delay
is zero, that [__]cancel_delayed_work() + queue_delayed_work_on()
makes the target item immediately executable while
mod_delayed_work_on() may induce delay of upto a full tick.
This somewhat subtle difference breaks some of the converted users.
e.g. block queue plugging uses delayed_work for deferred processing
and uses mod_delayed_work_on() when the queue needs to be immediately
unplugged. The above problem manifested as noticeably higher number
of context switches under certain circumstances.
The difference in behavior was caused by missing special case handling
for 0 delay in mod_delayed_work_on() compared to
queue_delayed_work_on(). Joonsoo Kim posted a patch to add it -
("workqueue: optimize mod_delayed_work_on() when @delay == 0")[1].
The patch was queued for 3.8 but it was described as optimization and
I missed that it was a correctness issue.
As both queue_delayed_work_on() and mod_delayed_work_on() use
__queue_delayed_work() for queueing, it seems that the better approach
is to move the 0 delay special handling to the function instead of
duplicating it in mod_delayed_work_on().
Fix the problem by moving 0 delay special case handling from
queue_delayed_work_on() to __queue_delayed_work(). This replaces
Joonsoo's patch.
[1] http://thread.gmane.org/gmane.linux.kernel/1379011/focus=1379012
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Anders Kaseorg <andersk@MIT.EDU>
Reported-and-tested-by: Zlatko Calusic <zlatko.calusic@iskon.hr>
LKML-Reference: <alpine.DEB.2.00.1211280953350.26602@dr-wily.mit.edu>
LKML-Reference: <50A78AA9.5040904@iskon.hr>
Cc: Joonsoo Kim <js1304@gmail.com>
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|
A rescue thread exiting TASK_INTERRUPTIBLE can lead to a task scheduling
off, never to be seen again. In the case where this occurred, an exiting
thread hit reiserfs homebrew conditional resched while holding a mutex,
bringing the box to its knees.
PID: 18105 TASK: ffff8807fd412180 CPU: 5 COMMAND: "kdmflush"
#0 [ffff8808157e7670] schedule at ffffffff8143f489
#1 [ffff8808157e77b8] reiserfs_get_block at ffffffffa038ab2d [reiserfs]
#2 [ffff8808157e79a8] __block_write_begin at ffffffff8117fb14
#3 [ffff8808157e7a98] reiserfs_write_begin at ffffffffa0388695 [reiserfs]
#4 [ffff8808157e7ad8] generic_perform_write at ffffffff810ee9e2
#5 [ffff8808157e7b58] generic_file_buffered_write at ffffffff810eeb41
#6 [ffff8808157e7ba8] __generic_file_aio_write at ffffffff810f1a3a
#7 [ffff8808157e7c58] generic_file_aio_write at ffffffff810f1c88
#8 [ffff8808157e7cc8] do_sync_write at ffffffff8114f850
#9 [ffff8808157e7dd8] do_acct_process at ffffffff810a268f
[exception RIP: kernel_thread_helper]
RIP: ffffffff8144a5c0 RSP: ffff8808157e7f58 RFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8107af60 RDI: ffff8803ee491d18
RBP: 0000000000000000 R8: 0000000000000000 R9: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
"This is mostly about unbreaking architectures that took the UAPI
changes in the v3.7 cycle, plus misc fixes."
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf kvm: Fix building perf kvm on non x86 arches
perf kvm: Rename perf_kvm to perf_kvm_stat
perf: Make perf build for x86 with UAPI disintegration applied
perf powerpc: Use uapi/unistd.h to fix build error
tools: Pass the target in descend
tools: Honour the O= flag when tool build called from a higher Makefile
tools: Define a Makefile function to do subdir processing
x86: Export asm/{svm.h,vmx.h,perf_regs.h}
perf tools: Fix strbuf_addf() when the buffer needs to grow
perf header: Fix numa topology printing
perf, powerpc: Fix hw breakpoints returning -ENOSPC
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Dave Jones reported a bug with futex_lock_pi() that his trinity test
exposed. Sometime between queue_me() and taking the q.lock_ptr, the
lock_ptr became NULL, resulting in a crash.
While futex_wake() is careful to not call wake_futex() on futex_q's with
a pi_state or an rt_waiter (which are either waiting for a
futex_unlock_pi() or a PI futex_requeue()), futex_wake_op() and
futex_requeue() do not perform the same test.
Update futex_wake_op() and futex_requeue() to test for q.pi_state and
q.rt_waiter and abort with -EINVAL if detected. To ensure any future
breakage is caught, add a WARN() to wake_futex() if the same condition
is true.
This fix has seen 3 hours of testing with "trinity -c futex" on an
x86_64 VM with 4 CPUS.
[akpm@linux-foundation.org: tidy up the WARN()]
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Reported-by: Dave Jones <davej@redat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: John Kacur <jkacur@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
In get_sample_period(), unsigned long is not enough:
watchdog_thresh * 2 * (NSEC_PER_SEC / 5)
case1:
watchdog_thresh is 10 by default, the sample value will be: 0xEE6B2800
case2:
set watchdog_thresh is 20, the sample value will be: 0x1 DCD6 5000
In case2, we need use u64 to express the sample period. Otherwise,
changing the threshold thru proc often can not be successful.
Signed-off-by: liu chuansheng <chuansheng.liu@intel.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull futex fix from Thomas Gleixner:
"Single fix for a long standing futex race when taking over a futex
whose owner died. You can end up with two owners, which violates
quite some rules."
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Handle futex_pi OWNER_DIED take over correctly
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Siddhesh analyzed a failure in the take over of pi futexes in case the
owner died and provided a workaround.
See: http://sourceware.org/bugzilla/show_bug.cgi?id=14076
The detailed problem analysis shows:
Futex F is initialized with PTHREAD_PRIO_INHERIT and
PTHREAD_MUTEX_ROBUST_NP attributes.
T1 lock_futex_pi(F);
T2 lock_futex_pi(F);
--> T2 blocks on the futex and creates pi_state which is associated
to T1.
T1 exits
--> exit_robust_list() runs
--> Futex F userspace value TID field is set to 0 and
FUTEX_OWNER_DIED bit is set.
T3 lock_futex_pi(F);
--> Succeeds due to the check for F's userspace TID field == 0
--> Claims ownership of the futex and sets its own TID into the
userspace TID field of futex F
--> returns to user space
T1 --> exit_pi_state_list()
--> Transfers pi_state to waiter T2 and wakes T2 via
rt_mutex_unlock(&pi_state->mutex)
T2 --> acquires pi_state->mutex and gains real ownership of the
pi_state
--> Claims ownership of the futex and sets its own TID into the
userspace TID field of futex F
--> returns to user space
T3 --> observes inconsistent state
This problem is independent of UP/SMP, preemptible/non preemptible
kernels, or process shared vs. private. The only difference is that
certain configurations are more likely to expose it.
So as Siddhesh correctly analyzed the following check in
futex_lock_pi_atomic() is the culprit:
if (unlikely(ownerdied || !(curval & FUTEX_TID_MASK))) {
We check the userspace value for a TID value of 0 and take over the
futex unconditionally if that's true.
AFAICT this check is there as it is correct for a different corner
case of futexes: the WAITERS bit became stale.
Now the proposed change
- if (unlikely(ownerdied || !(curval & FUTEX_TID_MASK))) {
+ if (unlikely(ownerdied ||
+ !(curval & (FUTEX_TID_MASK | FUTEX_WAITERS)))) {
solves the problem, but it's not obvious why and it wreckages the
"stale WAITERS bit" case.
What happens is, that due to the WAITERS bit being set (T2 is blocked
on that futex) it enforces T3 to go through lookup_pi_state(), which
in the above case returns an existing pi_state and therefor forces T3
to legitimately fight with T2 over the ownership of the pi_state (via
pi_state->mutex). Probelm solved!
Though that does not work for the "WAITERS bit is stale" problem
because if lookup_pi_state() does not find existing pi_state it
returns -ERSCH (due to TID == 0) which causes futex_lock_pi() to
return -ESRCH to user space because the OWNER_DIED bit is not set.
Now there is a different solution to that problem. Do not look at the
user space value at all and enforce a lookup of possibly available
pi_state. If pi_state can be found, then the new incoming locker T3
blocks on that pi_state and legitimately races with T2 to acquire the
rt_mutex and the pi_state and therefor the proper ownership of the
user space futex.
lookup_pi_state() has the correct order of checks. It first tries to
find a pi_state associated with the user space futex and only if that
fails it checks for futex TID value = 0. If no pi_state is available
nothing can create new state at that point because this happens with
the hash bucket lock held.
So the above scenario changes to:
T1 lock_futex_pi(F);
T2 lock_futex_pi(F);
--> T2 blocks on the futex and creates pi_state which is associated
to T1.
T1 exits
--> exit_robust_list() runs
--> Futex F userspace value TID field is set to 0 and
FUTEX_OWNER_DIED bit is set.
T3 lock_futex_pi(F);
--> Finds pi_state and blocks on pi_state->rt_mutex
T1 --> exit_pi_state_list()
--> Transfers pi_state to waiter T2 and wakes it via
rt_mutex_unlock(&pi_state->mutex)
T2 --> acquires pi_state->mutex and gains ownership of the pi_state
--> Claims ownership of the futex and sets its own TID into the
userspace TID field of futex F
--> returns to user space
This covers all gazillion points on which T3 might come in between
T1's exit_robust_list() clearing the TID field and T2 fixing it up. It
also solves the "WAITERS bit stale" problem by forcing the take over.
Another benefit of changing the code this way is that it makes it less
dependent on untrusted user space values and therefor minimizes the
possible wreckage which might be inflicted.
As usual after staring for too long at the futex code my brain hurts
so much that I really want to ditch that whole optimization of
avoiding the syscall for the non contended case for PI futexes and rip
out the maze of corner case handling code. Unfortunately we can't as
user space relies on that existing behaviour, but at least thinking
about it helps me to preserve my mental sanity. Maybe we should
nevertheless :)
Reported-and-tested-by: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1210232138540.2756@ionos
Acked-by: Darren Hart <dvhart@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Masaki found and patched a kallsyms issue: the last symbol in a
module's symtab wasn't transferred. This is because we manually copy
the zero'th entry (which is always empty) then copy the rest in a loop
starting at 1, though from src[0]. His fix was minimal, I prefer to
rewrite the loops in more standard form.
There are two loops: one to get the size, and one to copy. Make these
identical: always count entry 0 and any defined symbol in an allocated
non-init section.
This bug exists since the following commit was introduced.
module: reduce symbol table for loaded modules (v2)
commit: 4a4962263f07d14660849ec134ee42b63e95ea9a
LKML: http://lkml.org/lkml/2012/10/24/27
Reported-by: Masaki Kimura <masaki.kimura.kz@hitachi.com>
Cc: stable@kernel.org
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I've been trying to get hardware breakpoints with perf to work
on POWER7 but I'm getting the following:
% perf record -e mem:0x10000000 true
Error: sys_perf_event_open() syscall returned with 28 (No space left on device). /bin/dmesg may provide additional information.
Fatal: No CONFIG_PERF_EVENTS=y kernel support configured?
true: Terminated
(FWIW adding -a and it works fine)
Debugging it seems that __reserve_bp_slot() is returning ENOSPC
because it thinks there are no free breakpoint slots on this
CPU.
I have a 2 CPUs, so perf userspace is doing two perf_event_open
syscalls to add a counter to each CPU [1]. The first syscall
succeeds but the second is failing.
On this second syscall, fetch_bp_busy_slots() sets slots.pinned
to be 1, despite there being no breakpoint on this CPU. This is
because the call the task_bp_pinned, checks all CPUs, rather
than just the current CPU. POWER7 only has one hardware
breakpoint per CPU (ie. HBP_NUM=1), so we return ENOSPC.
The following patch fixes this by checking the associated CPU
for each breakpoint in task_bp_pinned. I'm not familiar with
this code, so it's provided as a reference to the above issue.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Jovi Zhang <bookjovi@gmail.com>
Cc: K Prasad <prasad@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1351268936-2956-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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|
Merge misc fixes from Andrew Morton:
"18 total. 15 fixes and some updates to a device_cgroup patchset which
bring it up to date with the version which I should have merged in the
first place."
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (18 patches)
fs/compat_ioctl.c: VIDEO_SET_SPU_PALETTE missing error check
gen_init_cpio: avoid stack overflow when expanding
drivers/rtc/rtc-imxdi.c: add missing spin lock initialization
mm, numa: avoid setting zone_reclaim_mode unless a node is sufficiently distant
pidns: limit the nesting depth of pid namespaces
drivers/dma/dw_dmac: make driver's endianness configurable
mm/mmu_notifier: allocate mmu_notifier in advance
tools/testing/selftests/epoll/test_epoll.c: fix build
UAPI: fix tools/vm/page-types.c
mm/page_alloc.c:alloc_contig_range(): return early for err path
rbtree: include linux/compiler.h for definition of __always_inline
genalloc: stop crashing the system when destroying a pool
backlight: ili9320: add missing SPI dependency
device_cgroup: add proper checking when changing default behavior
device_cgroup: stop using simple_strtoul()
device_cgroup: rename deny_all to behavior
cgroup: fix invalid rcu dereference
mm: fix XFS oops due to dirty pages without buffers on s390
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If one includes documentation for an external tool, it should be
correct. This is not:
1. Overriding the input to rngd should typically be neither
necessary nor desired. This is especially so since newer
versions of rngd support a number of different *types* of sources.
2. The default kernel-exported device is called /dev/hwrng not
/dev/hwrandom nor /dev/hw_random (both of which were used in the
past; however, kernel and udev seem to have converged on
/dev/hwrng.)
Overall it is better if the documentation for rngd is kept with rngd
rather than in a kernel Makefile.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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'struct pid' is a "variable sized struct" - a header with an array of
upids at the end.
The size of the array depends on a level (depth) of pid namespaces. Now a
level of pidns is not limited, so 'struct pid' can be more than one page.
Looks reasonable, that it should be less than a page. MAX_PIS_NS_LEVEL is
not calculated from PAGE_SIZE, because in this case it depends on
architectures, config options and it will be reduced, if someone adds a
new fields in struct pid or struct upid.
I suggest to set MAX_PIS_NS_LEVEL = 32, because it saves ability to expand
"struct pid" and it's more than enough for all known for me use-cases.
When someone finds a reasonable use case, we can add a config option or a
sysctl parameter.
In addition it will reduce the effect of another problem, when we have
many nested namespaces and the oldest one starts dying.
zap_pid_ns_processe will be called for each namespace and find_vpid will
be called for each process in a namespace. find_vpid will be called
minimum max_level^2 / 2 times. The reason of that is that when we found a
bit in pidmap, we can't determine this pidns is top for this process or it
isn't.
vpid is a heavy operation, so a fork bomb, which create many nested
namespace, can make a system inaccessible for a long time. For example my
system becomes inaccessible for a few minutes with 4000 processes.
[akpm@linux-foundation.org: return -EINVAL in response to excessive nesting, not -ENOMEM]
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
"This pull request contains three fixes.
Two are reverts of task_lock() removal in cgroup fork path. The
optimizations incorrectly assumed that threadgroup_lock can protect
process forks (as opposed to thread creations) too. Further cleanup
of cgroup fork path is scheduled.
The third fixes cgroup emptiness notification loss."
* 'for-3.7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
Revert "cgroup: Remove task_lock() from cgroup_post_fork()"
Revert "cgroup: Drop task_lock(parent) on cgroup_fork()"
cgroup: notify_on_release may not be triggered in some cases
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fix from Tejun Heo:
"This pull request contains one patch from Dan Magenheimer to fix
cancel_delayed_work() regression introduced by its reimplementation
using try_to_grab_pending(). The reimplementation made it incorrectly
return %true when the work item is idle.
There aren't too many consumers of the return value but it broke at
least ramster."
* 'for-3.7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: cancel_delayed_work() should return %false if work item is idle
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57b30ae77b ("workqueue: reimplement cancel_delayed_work() using
try_to_grab_pending()") made cancel_delayed_work() always return %true
unless someone else is also trying to cancel the work item, which is
broken - if the target work item is idle, the return value should be
%false.
try_to_grab_pending() indicates that the target work item was idle by
zero return value. Use it for return. Note that this brings
cancel_delayed_work() in line with __cancel_work_timer() in return
value handling.
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <444a6439-b1a4-4740-9e7e-bc37267cfe73@default>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
"Most of these are uprobes race fixes from Oleg, and their preparatory
cleanups. (It's larger than what I'd normally send for an -rc kernel,
but they looked significant enough to not delay them.)
There's also an oprofile fix and an uncore PMU fix."
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
perf/x86: Disable uncore on virtualized CPUs
oprofile, x86: Fix wrapping bug in op_x86_get_ctrl()
ring-buffer: Check for uninitialized cpu buffer before resizing
uprobes: Fix the racy uprobe->flags manipulation
uprobes: Fix prepare_uprobe() race with itself
uprobes: Introduce prepare_uprobe()
uprobes: Fix handle_swbp() vs unregister() + register() race
uprobes: Do not delete uprobe if uprobe_unregister() fails
uprobes: Don't return success if alloc_uprobe() fails
uprobes/x86: Only rep+nop can be emulated correctly
uprobes: Simplify is_swbp_at_addr(), remove stale comments
uprobes: Kill set_orig_insn()->is_swbp_at_addr()
uprobes: Introduce copy_opcode(), kill read_opcode()
uprobes: Kill set_swbp()->is_swbp_at_addr()
uprobes: Restrict valid_vma(false) to skip VM_SHARED vmas
uprobes: Change valid_vma() to demand VM_MAYEXEC rather than VM_EXEC
uprobes: Change write_opcode() to use FOLL_FORCE
uprobes: Move clear_thread_flag(TIF_UPROBE) to uprobe_notify_resume()
uprobes: Kill UTASK_BP_HIT state
uprobes: Fix UPROBE_SKIP_SSTEP checks in handle_swbp()
...
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Fix the warning:
kernel/module_signing.c:195:2: warning: format '%lu' expects type 'long unsigned int', but argument 3 has type 'size_t'
by using the proper 'z' modifier for printing a size_t.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent
Pull ftrace ring-buffer resizing fix from Steve Rostedt.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc into perf/urgent
Pull various uprobes bugfixes from Oleg Nesterov - mostly race and
failure path fixes.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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